Portable electronic devices becoming necessities of modern people owing to the easiness of carriage are evolving into multimedia devices providing a variety of services such as a voice and image calling function, an information input/output function, and data storage.
As the use of a multimedia service using a portable electronic device increases, information quantitation to process and display in the portable electronic device increase. This results in an increase of a concern for a portable electronic device with a touch screen capable of improving space utilization and increasing the size of a display unit.
The touch screen is an input/output device performing information input and display on one screen. According to this, if employing the touch screen, the portable electronic device can increase a display area since the portable electronic device does not require a separate input unit such as a keypad.
A touch input scheme of the portable electronic device with the touch screen includes a resistive touch scheme and a capacitive touch scheme.
If employing the resistive touch scheme, the portable electronic device determines a touch coordinate considering a pressure that is sensed at a time a user touches the touch screen with a finger and the like.
If employing the capacitive touch scheme, the portable electronic device determines the touch coordinate considering a variation of capacitance that occurs at a time the user touches the touch screen with the finger and the like.
If employing the capacitive touch scheme as above, the portable electronic device can suffer a touch recognition error due to the affection of the environment, because the portable electronic device operates by the capacitance variation. For example, the portable electronic device using the capacitive touch scheme can suffer the touch recognition error, because a capacitance variation error takes place due to the affection of the electric field and the magnetic field of the surroundings such as a fluorescent light, a microwave oven and the like. For another example, when a Travel Adapter (TA) of the unstable ground is connected to the portable electronic device, the portable electronic device may suffer the touch recognition error, because the capacitance variation is affected by unstable power supply by the TA.